The present disclosure relates to a coil electronic component and a method of manufacturing the same.
An inductor, which is a type of chip electronic component, is a representative passive element configuring an electronic circuit together with a resistor and a capacitor to remove noise therefrom.
A thin film type inductor may be manufactured by forming internal coil parts through plating, hardening a magnetic powder-resin composite in which magnetic powders and a resin are mixed with each other to manufacture a magnetic body, and then forming external electrodes on outer surfaces of the magnetic body.
A direct current (DC) resistance (Rdc), which is one of the main properties of the inductor, may be decreased as a cross-sectional area of an internal coil part is increased. In addition, inductance of the inductor may be increased as an area of the magnetic material through which magnetic flux passes is increased.
Therefore, in order to decrease the DC resistance (Rdc) and improve the inductance, the cross-sectional area of an internal coil and the area of a magnetic material may be increased.
Examples of a method for increasing the cross-sectional area of the internal coil part may include a method of increasing a width of the coil and a method of increasing a thickness of the coil.
However, when the width of the coil is increased, there is an increased risk of generating a short circuit between neighboring coils, and a limit to the number of turns of an implementable coil may occur, causing the area of the magnetic material to deteriorate with regard to efficiency. Furthermore, there may be a limitation with regard to implementation for a high capacity product.
Therefore, the thickness and width of a coil should be increased to give an internal coil part of the structure a high aspect ratio (AR).
An aspect ratio (AR) of an internal coil part may mean a value obtained by dividing the thickness of the coil by the width of the coil. As the thickness of the coil is increased by a greater amount than the width of the coil is increased, the higher aspect ratio (AR) may be implemented.
However, when the coil part is formed by performing a pattern plating method in which a plating resist is patterned and plated by an exposure and development process according to the related art, in order to increase the thickness of the coil, a thickness of the plating resist also needs to be increased. Since there is a limitation of the exposure process in which a lower portion of the plating resist is not smoothly exposed as the thickness of the plating resist is increased in thickness, it may be difficult to increase the thickness of the coil.
In addition, in order to maintain a form of the thick plating resist, the plating resist needs to have a predetermined width or greater. Since the width of the plating resist corresponds to an interval between the neighboring coils, the interval between the neighboring coils may be increased. As a result, there is a limitation in improving DC resistance (Rdc) and inductance (Ls) characteristics.
In the related art, a process is disclosed in which a first plating conductor pattern is formed after a first resist pattern is formed by exposing and developing a resist film, and a second plating conductor pattern is formed after forming a second resist pattern by again exposing and developing the first plating conductor pattern onto the first resist pattern, in order to solve an exposure limitation according to a thickness of the resist film.
When the internal coil part is formed by performing only the pattern plating method, however, there is a limitation in increasing the cross-sectional area of the internal coil part. Furthermore, since the interval between the neighboring coils is increased, it is difficult to improve DC resistance (Rdc) and inductance (Ls) characteristics.
In addition, in order to form the coil part of the structure having the high aspect ratio (AR), a method of implementing the coil part by adding anisotropic plating onto a plating layer by isotropic plating has been generally attempted.
The above-mentioned anisotropic plating scheme may implement the remaining height of the coil required after forming a seed pattern by the anisotropic plating. According to the above-mentioned scheme, since a shape of the coil, which is a fan shape, has decreased uniformity, it may affect a distribution of the DC resistance (Rdc).
In addition, according to the above-mentioned scheme, since the shape of the coil is bent, it may be difficult to form an insulating layer on the coil pattern. Therefore, a non-insulating space between the coil patterns may occur, thereby causing a defect.